In the workplace, there are some things you just don't do if you want to keep your job. You don't slack off, you try not to offend your clients or coworkers, and you definitely don't complain about how much you hate your boss.

The same can be said of social media. Unless you're looking to get fired, tweeting about how little you work, how inferior your coworkers are or how loathesome you find your superior probably isn't a good idea. After all, you never know who's looking at your profile or where your tweets will wind up -- take it from Anthony Weiner.

1. Remember, the Internet never forgets
Remember that time you had too much to drink at happy hour? If you happened to post a photo a Facebook, so will everyone else. "Common sense is a huge factor here," according to social media guidelines posted by Adidas. "If you are about to publish something that makes you even the slightest bit uncomfortable, review," says the sportswear manufacturer.

2. Consider the consequences
Adidas also asks employees to think before they tweet. "Imagine you are sitting in a sales meeting and your client brings out a printout of a colleague's post that states that the product you were about to sell 'completely sucks,'" says the company. "Talk about a tough pitch."

3. When in doubt, do not post
The Coca Cola Company suggests employees exercise sound judgement and common sense on social media as well. "Associates are personally responsible for their words and actions, wherever they are," the company says. As online spokespeople, employees are responsible for making sure their posts are accurate and don't disclose any private information about the company. And if there is any doubt, says the beverage company, "DO NOT post."

4. Speak for yourself ... and your company
Coke also warns employees that in social media, business is personal and personal is business. "The Company respects the free speech rights of all of its associates, but you must remember that customers, colleagues and supervisors often have access to the online content you post. Keep this in mind when publishing information online that can be seen by more than friends and family, and know that information originally intended just for friends and family can be forwarded on."

5. Know you're always "On"According to PR firm AMP3, however, you should assume that someone's always watching."Keep in mind," the company tells employees, "that while we all have the occasional work frustration, Facebook and Twitter are not the best venues in which to air them, as those comments are available to your clients and coworkers."

6. Play Nice
We've all been told that if you don't have anything nice to say, don't say anything at all. But it turns out that Mom's advice can help you get along in social media as well as the school yard. "You can have an edge without being obscene." says AMP3. The PR firm instructs employees to "demonstrate respect for others’ points of view, even when they’re not offering the same in return."

7. Be careful not to over-share
We're all guilty of over-sharing on social media -- who hasn't posted a photo of what they had for breakfast or an update about their adorable dog? But according to Intel and its social guidelines, it's important to draw a line. Personal opinions about the workplace or coworkers are probably going too far. So are posts about personal hygiene. "Once you hit 'share,' you usually can’t get it back," Intel tells employees.

8. Don't be creepy
"You know the guy," Flickr warns users in its community guidelines, "Don't be that guy." Sage advice for any social media user, especially those trying to hold on to a job.